Airbags and other pliable and inflatable restraints are being designed using releasable tethers to selectively modify the performance of the airbag or restraint cushion during deployment. In certain airbags, for example, tension in an associated tether maintains a valve controlling an airbag vent in a closed position. At some point during or after deployment of the inflatable device, tension in the tether may be relieved to permit actuation of the vent valve and subsequent release of airbag gases.
Nevertheless, certain challenges remain. One challenge that remains is the ability to control the pressure differential between various regions of the airbag and the geometry of the various regions of the airbag as the airbag deployment progresses. Stated another way, the ability to control the dynamic volumes of the airbag at the upper or head/neck region, at the intermediate or thoracic region, and/or at the bottom of the airbag, remains a challenge. In general, with the onset of almost instantaneous pressure in the airbag upon a collision event, various concerns including the size and position of the occupant adjacent the deploying airbag warrant some type of volume control of the various regions of the airbag to control the force that might typically occur due to the onset of airbag pressure. State of the art airbags do not typically differentiate between the various regions and therefore, it would be an improvement in the art to create a pressure differential based on specific design criteria for various applications.
The embodiments of the present invention provide a novel tethered volume control mechanism or system within an airbag.